Sérgio Paulo Hilgenberg

Physical-chemical characteristics of whitening toothpaste and evaluation of its effects on enamel roughness

This in vitro study evaluated the physical-chemical characteristics of whitening toothpastes and their effect on bovine enamel after application of a bleaching agent (16% carbamide peroxide). Physical-chemical analysis was made considering mass loss by desiccation, ash content and pH of the toothpastes. Thirty bovine dental enamel fragments were prepared for roughness measurements. The samples were subjected to bleaching treatments and simulated brushing: G1. Sorriso Dentes Brancos (Conventional toothpaste), G2. Close-UP Whitening (Whitening toothpaste), and G3. Sensodyne Branqueador (Whitening toothpaste). The average roughness (Ra) was evaluated prior to the bleaching treatment and after brushing. The results revealed differences in the physical-chemical characteristics of the toothpastes (p < 0.0001). The final Ra had higher values (p < 0.05) following the procedures. The mean of the Ra did not show significant differences, considering toothpaste groups and bleaching treatment. Interaction (toothpaste and bleaching treatment) showed significant difference (p < 0.0001). The whitening toothpastes showed differences in their physical-chemical properties. All toothpastes promoted changes to the enamel surface, probably by the use of a bleaching agent.

Characterization of Dentifrices Containing Desensitizing Agents, Triclosan or Whitening Agents: EDX and SEM Analysis

Dentifrices with different compositions are available on the market, but there is limited information about their properties. The aim of this in vitro study was to evaluate the physicochemical characteristics of 12 dentifrices divided into three categories, as containing desensitizing agents, Triclosan or whitening agents. Desiccation loss/residue analysis: 5 g of dentifrice was weighed five times for each group. pH analysis: 5 g of dentifrice were diluted in three parts of distilled water and analyzed using a digital potentiometer. Scanning electron microscopy (SEM): analysis of ashes, shape and size of the particles. Energy-dispersive x-ray spectroscopy (EDX): identification of the abrasive elements. Data were analyzed using ANOVA, Bonferroni post hoc test (α=0.05). Desiccation loss: 38.21% to 65.83%. Dentifrices containing Triclosan and desensitizing agents showed statistically significant differences among them (p<0.05). Whitening dentifrices showed statistically significant differences between Close-Up Whitening and Sensodyne Branqueador (44.72%, 65.83%, respectively). Most dentifrices presented neutral or basic pH. Different shape and size particles were observed in the SEM analysis. Abrasive elements were identified in the EDX. These results demonstrate that the evaluated dentifrices had different properties and their composition influences directly their characteristics, thus resulting in a more or less abrasive action on tooth surface. Knowing the characteristics of the dentifrices is important to indicate the ideal product for each case.

EXPRESSÃO DIFERENCIAL DE CITOCINAS NOS LADOS DE PRESSÃO E TENSÃO DURANTE A MOVIMENTAÇÃO ORTODÔNTICA

The aim of this work was evaluate the pro and antinflamatory cytokines expression, collagen type-I, remodeling tecidual mediator (MMP-1) and its inhibitor (TIMP-1), osteoclastogenic factors (RANKL) and osteoblastogenics (CBFA-1), in the different sides under tension forces and pressure, in the orthodontic movement. Quantitative examinations of reaction in chain of polymerase was realized (RealTime-PCR), using mRNA proceeding from samples of periodontal tooth ligament submitted to orthodontic forces. Tooth that has orthodontic extraction indication was utilized, after application of forces in maxillary and no-movement tooth in the control group. The results showed that the side of pressure had more expression of TGF-beta, TNF-a, RANKL e MMP1, and less expression of COL-1 when compared with control group, while tension side showed more expression of TGF-beta, IL-10, COL-1 and CBFA-1. Comparing the both sides was observed more expression of IL-10, COL-1 and CBFA-1 in the tension side, and more expression of TNF-a, RANKL and MMP-1 in the pressure side. The results indicate that cytokines standard determines the nature of the tecidual reply to the orthodontic force, modifying and guiding the equilibry between reabsortion and neoformation of the bone.